A specific tool, referred to herein as a sealing plug, is used in aircraft assembly lines to seal a drainage circuit of an engine pylon in a simple and rapid manner. The seal created using such a tool allows verifying and testing the fluid-tightness of the aircraft fuel system during assembly. The plug generally comprises a body presenting a first end having an end piece fitted with a gasket. During the test, the end piece closes off a pipe and the plug is held in place by an angle bracket acting on the body of the plug while attached to a protective support of the aircraft.
The attached FIG. 1 illustrates a plug of the prior art. In this figure, one will recognize a pipe 2 which constitutes part of a fuel circuit in an engine pylon of an aircraft, as well as a plate 4 forming a wall. This plate 4 has a bore hole 6 which provides access to the pipe 2, the latter extending perpendicularly to and on one side of the plate 4.
On the side of the plate 4 opposite the pipe 2, one will note the presence of an end piece 8 which supports a gasket 10. This end piece 8 is equipped with an angle bracket 12 which enables attachment to a support (not represented) of the corresponding aircraft.
A problem which arises with the implementation of such a prior art plug concerns the attachment of the angle bracket. The area where the end piece and its angle bracket are to be positioned is difficult to access. Placement of the plug may therefore take time.
When in certain cases, as illustrated in FIG. 1, access to the pipe to be sealed occurs through a bore hole in a wall of the aircraft, sometimes the pipe to be sealed is not perfectly centered relative to said bore hole. An offset (illustrated in FIG. 1) therefore appears between the center (or axis) of this bore hole and the center (or axis) of the pipe, which makes it difficult for the end piece and its gasket to establish the seal. One solution consists of sealing only the bore hole made in the wall of the aircraft. However, because of the surface condition of this bore hole, it is not possible to guarantee a good fluid-tight seal. It is therefore advisable to establish a seal at the pipe.
The problem which then arises with a plug of the prior art as described above is that it needs to be adjusted for the offset between the axis of the bore hole and that of the pipe. This is a delicate operation and may require, in addition to the plug, using industrial silicone for example to complete the seal. In addition, access is difficult and complicates the operation, similarly to the conditions for placement of the angle bracket.
Lastly, it is often proposed to have different engines originating from different engine manufacturers in the same type of aircraft. The diameters of the openings to be sealed may then vary and it is necessary to have a sealing tool for each of the engine devices proposed.